Pages 21-24
Generally speaking, it is profitable for weight, volume and manufacturing expenses to adopt extended heating surface for the heat exchanger in which the temperature difference between heating and heated fluid is small. It is very important to use the studs of the most suitable size when studded tubes are used for extended heating surface. In our factory, studded tubes have been adopted for heating tubes of exhaust gas boiler in the last several years, and it was found that they were better in all respects than the bare tubes. By the recent inspection of the studded tubes taken from the exhaust gas boiler after long running, it was found that there was no necessity to take special considerations on the design and operation of the boiler, compared with the boiler with the bare tubes.